null_blk: use async queue restart helper
[cascardo/linux.git] / drivers / block / null_blk.c
index 5c8ba54..09e3c0d 100644 (file)
@@ -18,6 +18,7 @@ struct nullb_cmd {
        struct bio *bio;
        unsigned int tag;
        struct nullb_queue *nq;
+       struct hrtimer timer;
 };
 
 struct nullb_queue {
@@ -49,17 +50,6 @@ static int null_major;
 static int nullb_indexes;
 static struct kmem_cache *ppa_cache;
 
-struct completion_queue {
-       struct llist_head list;
-       struct hrtimer timer;
-};
-
-/*
- * These are per-cpu for now, they will need to be configured by the
- * complete_queues parameter and appropriately mapped.
- */
-static DEFINE_PER_CPU(struct completion_queue, completion_queues);
-
 enum {
        NULL_IRQ_NONE           = 0,
        NULL_IRQ_SOFTIRQ        = 1,
@@ -142,8 +132,8 @@ static const struct kernel_param_ops null_irqmode_param_ops = {
 device_param_cb(irqmode, &null_irqmode_param_ops, &irqmode, S_IRUGO);
 MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer");
 
-static int completion_nsec = 10000;
-module_param(completion_nsec, int, S_IRUGO);
+static unsigned long completion_nsec = 10000;
+module_param(completion_nsec, ulong, S_IRUGO);
 MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns");
 
 static int hw_queue_depth = 64;
@@ -180,6 +170,8 @@ static void free_cmd(struct nullb_cmd *cmd)
        put_tag(cmd->nq, cmd->tag);
 }
 
+static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer);
+
 static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
 {
        struct nullb_cmd *cmd;
@@ -190,6 +182,11 @@ static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
                cmd = &nq->cmds[tag];
                cmd->tag = tag;
                cmd->nq = nq;
+               if (irqmode == NULL_IRQ_TIMER) {
+                       hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
+                                    HRTIMER_MODE_REL);
+                       cmd->timer.function = null_cmd_timer_expired;
+               }
                return cmd;
        }
 
@@ -220,6 +217,11 @@ static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait)
 
 static void end_cmd(struct nullb_cmd *cmd)
 {
+       struct request_queue *q = NULL;
+
+       if (cmd->rq)
+               q = cmd->rq->q;
+
        switch (queue_mode)  {
        case NULL_Q_MQ:
                blk_mq_end_request(cmd->rq, 0);
@@ -234,51 +236,29 @@ static void end_cmd(struct nullb_cmd *cmd)
        }
 
        free_cmd(cmd);
+
+       /* Restart queue if needed, as we are freeing a tag */
+       if (queue_mode == NULL_Q_RQ && blk_queue_stopped(q)) {
+               unsigned long flags;
+
+               spin_lock_irqsave(q->queue_lock, flags);
+               blk_start_queue_async(q);
+               spin_unlock_irqrestore(q->queue_lock, flags);
+       }
 }
 
 static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
 {
-       struct completion_queue *cq;
-       struct llist_node *entry;
-       struct nullb_cmd *cmd;
-
-       cq = &per_cpu(completion_queues, smp_processor_id());
-
-       while ((entry = llist_del_all(&cq->list)) != NULL) {
-               entry = llist_reverse_order(entry);
-               do {
-                       struct request_queue *q = NULL;
-
-                       cmd = container_of(entry, struct nullb_cmd, ll_list);
-                       entry = entry->next;
-                       if (cmd->rq)
-                               q = cmd->rq->q;
-                       end_cmd(cmd);
-
-                       if (q && !q->mq_ops && blk_queue_stopped(q)) {
-                               spin_lock(q->queue_lock);
-                               if (blk_queue_stopped(q))
-                                       blk_start_queue(q);
-                               spin_unlock(q->queue_lock);
-                       }
-               } while (entry);
-       }
+       end_cmd(container_of(timer, struct nullb_cmd, timer));
 
        return HRTIMER_NORESTART;
 }
 
 static void null_cmd_end_timer(struct nullb_cmd *cmd)
 {
-       struct completion_queue *cq = &per_cpu(completion_queues, get_cpu());
+       ktime_t kt = ktime_set(0, completion_nsec);
 
-       cmd->ll_list.next = NULL;
-       if (llist_add(&cmd->ll_list, &cq->list)) {
-               ktime_t kt = ktime_set(0, completion_nsec);
-
-               hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL_PINNED);
-       }
-
-       put_cpu();
+       hrtimer_start(&cmd->timer, kt, HRTIMER_MODE_REL);
 }
 
 static void null_softirq_done_fn(struct request *rq)
@@ -376,6 +356,10 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx,
 {
        struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
 
+       if (irqmode == NULL_IRQ_TIMER) {
+               hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+               cmd->timer.function = null_cmd_timer_expired;
+       }
        cmd->rq = bd->rq;
        cmd->nq = hctx->driver_data;
 
@@ -459,8 +443,9 @@ static void null_lnvm_end_io(struct request *rq, int error)
        blk_put_request(rq);
 }
 
-static int null_lnvm_submit_io(struct request_queue *q, struct nvm_rq *rqd)
+static int null_lnvm_submit_io(struct nvm_dev *dev, struct nvm_rq *rqd)
 {
+       struct request_queue *q = dev->q;
        struct request *rq;
        struct bio *bio = rqd->bio;
 
@@ -485,7 +470,7 @@ static int null_lnvm_submit_io(struct request_queue *q, struct nvm_rq *rqd)
        return 0;
 }
 
-static int null_lnvm_id(struct request_queue *q, struct nvm_id *id)
+static int null_lnvm_id(struct nvm_dev *dev, struct nvm_id *id)
 {
        sector_t size = gb * 1024 * 1024 * 1024ULL;
        sector_t blksize;
@@ -538,7 +523,7 @@ static int null_lnvm_id(struct request_queue *q, struct nvm_id *id)
        return 0;
 }
 
-static void *null_lnvm_create_dma_pool(struct request_queue *q, char *name)
+static void *null_lnvm_create_dma_pool(struct nvm_dev *dev, char *name)
 {
        mempool_t *virtmem_pool;
 
@@ -556,7 +541,7 @@ static void null_lnvm_destroy_dma_pool(void *pool)
        mempool_destroy(pool);
 }
 
-static void *null_lnvm_dev_dma_alloc(struct request_queue *q, void *pool,
+static void *null_lnvm_dev_dma_alloc(struct nvm_dev *dev, void *pool,
                                gfp_t mem_flags, dma_addr_t *dma_handler)
 {
        return mempool_alloc(pool, mem_flags);
@@ -780,7 +765,9 @@ out:
 
 static int __init null_init(void)
 {
+       int ret = 0;
        unsigned int i;
+       struct nullb *nullb;
 
        if (bs > PAGE_SIZE) {
                pr_warn("null_blk: invalid block size\n");
@@ -813,19 +800,6 @@ static int __init null_init(void)
 
        mutex_init(&lock);
 
-       /* Initialize a separate list for each CPU for issuing softirqs */
-       for_each_possible_cpu(i) {
-               struct completion_queue *cq = &per_cpu(completion_queues, i);
-
-               init_llist_head(&cq->list);
-
-               if (irqmode != NULL_IRQ_TIMER)
-                       continue;
-
-               hrtimer_init(&cq->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-               cq->timer.function = null_cmd_timer_expired;
-       }
-
        null_major = register_blkdev(0, "nullb");
        if (null_major < 0)
                return null_major;
@@ -835,22 +809,29 @@ static int __init null_init(void)
                                                                0, 0, NULL);
                if (!ppa_cache) {
                        pr_err("null_blk: unable to create ppa cache\n");
-                       return -ENOMEM;
+                       ret = -ENOMEM;
+                       goto err_ppa;
                }
        }
 
        for (i = 0; i < nr_devices; i++) {
-               if (null_add_dev()) {
-                       unregister_blkdev(null_major, "nullb");
-                       goto err_ppa;
-               }
+               ret = null_add_dev();
+               if (ret)
+                       goto err_dev;
        }
 
        pr_info("null: module loaded\n");
        return 0;
-err_ppa:
+
+err_dev:
+       while (!list_empty(&nullb_list)) {
+               nullb = list_entry(nullb_list.next, struct nullb, list);
+               null_del_dev(nullb);
+       }
        kmem_cache_destroy(ppa_cache);
-       return -EINVAL;
+err_ppa:
+       unregister_blkdev(null_major, "nullb");
+       return ret;
 }
 
 static void __exit null_exit(void)